Synthesis under usual conditions, X-ray photoelectron spectroscopy and magnetic properties of Re1−xMnxO2 oxides with rutile structure

Solid solutions Re1−xMnxO2 (x = 0; 0.08; 0.21) with a tetragonal rutile-type structure (sp. gr. P42/mnm, z = 2) have been synthesized from NH4ReO4, KReO4 and KMnO4 in argon atmosphere at 450–520 °C in a quartz cell. According to XPS measurements, Mn in solid solutions Re1−xMnxO2 is present as Mn3+ and Mn2+ cations, while the degree of oxidation of Re partly increases to penta- or hexavalent state. A transition of ReO2 presumably in the antiferromagnetic state at 41 K was for the first time established by magnetic measurements. Along with the anomaly at 41 K, the second magnetic transitions at 6.5 K (x = 0.08) and 11 K (x = 0.21) was registered in these solid solutions.